1. Field of the Invention
The present invention relates to a shock absorbing member which alleviates an impact generated with respect to a cam slider supporting base when a cam slider configured to be slid in the horizontal direction on a cam surface of a cam driver for machining is returned to its original position, and a method of mounting the same, in a cam device of a press die.
2. Prior Art
Conventionally, in a case where a large metallic panel such as an automotive vehicle body is press-formed with a die including a lower fixed die and an upper movable die in terms of the vertical direction, a cam device as shown in FIGS. 6A and 6B, for example, is mounted on the die in order to form a hole on a side surface of a press-formed product or bend an edge of the same.
The cam device is a so-called aerial cam device, and includes a cam driver 2 configured to be fixedly mounted on a fixed die A, a cam slider 3 having a cam surface 3a which comes into sliding contact with a sliding surface 2a of the cam driver 2 and a machining tool, and a cam slider supporting base 4 configured to be mounted on a movable die B which moves upward and downward and is configured to movably support the cam slider 3 (see JP-A-2000-218320).
Provided between a rear end portion of the cam slider 3 and a one-side supporting strip of the cam slider supporting base 4 is a shock absorbing unit 10 configured to alleviate an impact generated when the cam slider 3 is returned to its original position by an urging force of a resilient member 5 such as a coil spring when the movable die B is moved from a closed position (see FIG. 6B) to an open position (see FIG. 6A).
The shock absorbing unit 10 having a shock absorbing member 11 formed into a cylindrical shape with a urethane material which is inserted into a mounting hole 4a of the cam slider supporting base 4, and is attached and fixed with adhesive agent 12 is known as shown in FIG. 7A. As shown in FIG. 7B, there is also a shock absorbing member 13 being formed of a urethane material and having a leg portion 13b inserted into the mounting hole 4a of the cam slider supporting base 4 and fixed thereto or screwed therein so that an outside portion corresponds to a deflecting margin portion 13a having a diameter larger than the mounting hole 4a added with a height including a compression stroke “s” set therein. Furthermore, there is a known shock absorbing member 14 having a through hole at a center portion thereof to allow a bolt 15 and a collar 16 to be inserted therein, thereby screwing into the cam slider supporting base 4 as shown in FIG. 7C.
However, in the above conventional cam slider shock absorbing member of the cam device, for example, in an example shown in FIG. 7A, the stroke “s” cannot be set to large value, and the adhesive agent 12 is needed. Therefore, it takes a lot of trouble to execute the work and, in addition, the shock absorbing member cannot be replaced easily and is easy to break. In an example shown in FIG. 7B, a protruding amount a from a wall surface 4b of the cam slider supporting base 4 is large and hence a space required for the shock absorbing member is increased. In addition, since an exposed portion is large, it can easily come apart by application of an external force. In an example shown in FIG. 7C, the number of components such as the bolt and the collar is increased, and hence the cost is increased and, in addition, it takes a lot of trouble to execute the work such as installation of the shock absorbing member or formation of the screw hole.